From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A19E7C433DB for ; Thu, 25 Feb 2021 11:16:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5FEBC64EF1 for ; Thu, 25 Feb 2021 11:16:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234030AbhBYLQP (ORCPT ); Thu, 25 Feb 2021 06:16:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:55758 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233632AbhBYLPx (ORCPT ); Thu, 25 Feb 2021 06:15:53 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id D678C64F0A; Thu, 25 Feb 2021 11:15:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614251710; bh=Oi+SraEGODKqOTiXfFk5238MjRgZX5tRsLs16fRyUXI=; h=From:To:Cc:Subject:Date:From; b=CWcpDMBIlZJJ3+vI1ouKIBd0UyOm1DiD/+tYUCeitD+4sfskrwqhZ4NjnO4y2+v54 UrvXh+3gteq66kAtOq69lHW92VZt8O4SlDwq9Ep/kLS0sxW24+lT+Lt0kBod3GCirj fjhNN7RTo4czWD5qkgLP7KbyKUBtNlyVam+SBMUgrgnZkbf1bHl6/EVBZ2mlKmF8/W y3yScuRGsWQKmp7mBUtZFAKRxpaOF60HdzKbxym96N3zpVGK/60nRoDYfm2ZN8Fwrn Pd2pT69P6k5RcVYbb+yDruzeNuEmulccVhkpPaZJkE6s2K1BgjGhdecFUAjFFXgeu3 0gGJpHpQtFZjQ== From: Arnd Bergmann To: Geert Uytterhoeven Cc: Arnd Bergmann , Kees Cook , Greg Ungerer , linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org Subject: [PATCH] [RFT] m68k: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION Date: Thu, 25 Feb 2021 12:14:45 +0100 Message-Id: <20210225111505.1936566-1-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnd Bergmann While experimenting with CONFIG_TRIM_UNUSED_KSYMS across architectures, I noticed that this unsurprisingly works best when combined with the --gc-sections linker flag, which is not currently allowed on m68k. Enabling it with this patch shows significant improvements for kernel size, looking at m68k defconfig with gcc-10, I get 4005135 1374302 167108 5546545 54a231 vmlinux-normal 3916254 1378078 167108 5461440 5355c0 vmlinux+trim 4012933 1362514 164280 5539727 54878f vmlinux+gcsection 3797884 1334194 164640 5296718 50d24e vmlinux+gcsection+trim There are probably bugs somewhere, but if someone is able to test this patch and fix any issues that come up, would be a useful improvement for memory-limited machines. Link: https://lore.kernel.org/lkml/CAK8P3a05VZ9hSKRzVTxTn+1nf9E+gqebJWTj6N23nfm+ELHt9A@mail.gmail.com/ Signed-off-by: Arnd Bergmann --- arch/m68k/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index c186733562b3..5f1aafa7b2e2 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -24,6 +24,7 @@ config M68K select HAVE_DEBUG_BUGVERBOSE select HAVE_FUTEX_CMPXCHG if MMU && FUTEX select HAVE_IDE + select HAVE_LD_DEAD_CODE_DATA_ELIMINATION select HAVE_MOD_ARCH_SPECIFIC select HAVE_UID16 select MMU_GATHER_NO_RANGE if MMU -- 2.29.2